A Randomised Controlled Trial of a Brief Planning Intervention to Promote Physical Activity

Detailed Description A health gap exists such that people of low socioeconomic status are more inclined to incur poor health than those of high socioeconomic status (Marmot, 2005). Differences in modifiable lifestyle factors between high- and low-socioeconomic groups, such as differences in physical activity levels, have been implemented in contributing to this health gap. Additionally, interventions created to redress this health gap can unintentionally have the reverse effect of increasing health inequalities as more affluent individuals are more likely to take up and adhere to behaviour change interventions, thus creating intervention-generated inequalities (White et al., 2009). Subsequently, there has been an increased call for interventions designed to promote healthy lifestyle behaviours, including physical activity, to be targeted towards specific groups of individuals including people with low-socioeconomic status (White et al., 2009). However, socioeconomic status is typically operationalised using a single measure such as educational status, yet socioeconomic status represents availability of and access to resources (Psaki et al., 2014), including those that access physical activity.

Socioeconomic measures can broadly be categorised as individual level factors, such as income, education and occupation, and area-level indicators or neighbourhood deprivation indices (Galobardes et al., 2006a, 2006b) such as the Index of Multiple Deprivation. While each measure captures a specific aspect of socioeconomic status, having its own relative strengths and limitations, there is a tendency in research to use a single measure (such as either income or education level) interchangeably to capture the full scope of socioeconomic status (Geyer et al., 2006). This is based upon the assumption that one socioeconomic measure taps into the underlying features of another aspect of socioeconomic status, despite little being known about the effect each socioeconomic status measure has upon physical activity intervention outcomes.

The purpose of this study is to consider the effect the different measures of socioeconomic status, specifically income, occupational status, education and area deprivation, have upon the effectiveness of an established implementation intentions-based intervention (the volitional help sheet) designed to increase physical activity and which has been shown to increase physical activity among manual workers (Armitage & Arden, 2010).

This study will seek to address the following research questions;

1. Does the volitional help sheet (VHS) increase gym attendance among new gym registrants?
2. Does the way in which socioeconomic status is measured moderate the effects of the volitional help sheet on gym attendance between low and high -income, - education, -occupation and -area deprivation groups?